This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Degenerative joint disease is one of the most frequent causes of physical disability among adults. Early diagnosis, characterization of the stage of degeneration, and monitoring the response of articular surfaces to treatment is essential. Today, joint disease detection is limited to visualization of joint surfaces by arthroscopy, radiography, CAT, MRI and ultrasound. None of these techniques gives a resolution better that 100 micron. Using MPM (with the development of a endoscope) for imaging articular cartilage/synovial structure may provide significant benefit to diagnosing ability and accuracy. The first step toward the ultimate goal is to study animal joints using MPM and discern signs of disease.